Ski binding, particularly a ski safety binding



V F. AVCIN March 16, 1965 SKI BINDING, PARTICULARLY A SKI SAFETY BINDING Filed May 31, 1963 FIG.4

FIG.3

m u v V EM C m R F United States Patent 3,173,702 SKI BINDING, PARTICULARLY A SKI SAFETY BINDING France Avin, Ljubljana, Yugloslavia, assignor to Heinrich Wunder, Rothschwaige, near Dachau, Germany Filed May 31, 1963, Ser. No. 284,693 Claims priority, application Yugoslavia, Jane 1, 1962, 7% Claims. (Cl. 28tl1l.35)

This invention relates to a ski binding, particularly to a ski safety binding, by which the skiing boot is retained on the ski in skiing position, but is automatically released under the influence of an increased pressure acting in the direction toward the tip of the ski, for instance, when the skier falls forwardly.

Various types of ski safety bindings are known. They have the object of avoiding fractures of and injury to the skier as far as possible. This object is accomplished in various ways, the binding releasing the foot under an excessive load. In this connection, it is necessary to distinguish two cases, namely, an excessive torsional load and an excessive fiexural load. A torsional load is due to rotary movements of the legs relative to the skier and the flexural load is due to an inclination of the body in the direction of the longitudinal axis of the skis.

In the previously known types of ski safety bindings, protection against excessive torsional loads is afforded by a safety jaw laterally pivotally movably mounted near the toe of the boot or a similar device near the heel of the boot. On the other hand, protection against fiexural loads is afforded in all known types by a tripping device arranged in the tightener of the binding or adjacent to the tightener in the tension cable.

These types of safety bindings generally afford adequate protection from injury due to excessive torsional loads. On the other hand, the protection from injury due to excessive flexural loads is inadequate, as is proved by the relatively large number of accidents, particularly of strained ankles, boot edge fractures or even strained Achilles tendons. The reason for this inadequacy or unreliability of the protection afforded by the presently known ski safety bindings resides in that the large fiexural load occurring in the case of a forward fall is transmitted to the tripping device by the tension cable, which is always angled at guide hooks, and in that hightly different frictional forces may occur in different cases in one and the same binding due to the tension and angling of the cable so that the tensile force applied to the protective device may greatly .vary and the latter will not always respond to the desired or adjusted load.

It is an object of the invention to provide a ski safety binding which reliably releases the boot in response to excessively high fiexural loads. According to the invention, this object is achieved in that the safety binding comprises a safety jaw which is atlixed to the ski and holds down the toe of the boot, means secured to the ski for urging the heel of the boot against the safety jaw, said safety jaw having a guide rail firmly secured to the ski and a jaw head displaceable along said guide rail in the longitudinal direction of the ski, means disposed between the jaw head and the guide rail for holding the jaw head in operative position and for releasing the same under the influence of an increased pressure acting in the direction toward the tip of the ski, said jaw head having a sole holder engaging the toe of the boot.

It is another feature of the invention that the means disposed between the jaw head and the guide rail consist of a flexure-responsive locking device comprising a resilient detent engaging a snap hole.

Finally, it is a feature of the invention that the detent is inserted in a hollow pivot pin, around which the jaw head is pivotally mounted.

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binding 1 comprises a cable 4 which embraces the heel 2 of the skiing boot 3 and incorporates two tension springs 6 on opposite sides of the ski 5. The tension cable 4 is guided in hooks '7 and 8 along the longitudinal sides of the ski and at its end remote from the tip of the ski is connected to a tightener 9, by which the cable is tightened and relaxed. In addition to the hooks 7 and 8, an additional hook 1i), which is nearer to the heel 2 of the boot, is provided on the longitudinal sides of the ski for receiving the cable when a stronger downward tension on the heel is desired.

Adjacent to the toe of the boot 3, the sole 11 of the boot 3 is gripped by a safety jaw 12, against which it is forced by the tensile force of the tension cable 4. The safety jaw 12 has a jaw head 14, which is pivotally mounted around the hollow pivot pin 13 and which is firmly connected to a baseplate or slide means 15 for guiding the jaw head 14 in the longitudinal direction of the ski on a guide rail or baseplate 1'7 secured by screws 16 to the ski 5.

In unloaded condition or under an allowable torsional load, the jaw head 14 is held in its intermediate position by a torsion-responsive locking device, which comprises a detent ball 19, which is disposed in the longitudinal center line of the jaw head 14 and accommodated in a vertical bore 18 and by a spring 26 extending in the longitudinal direction of the bore 18 is urged against a locking means formed in the base 15 and consisting of a snap hole 21. The snap hole 21 is surrounded by an upturned rim 22, which forms the seat for the ball 19. The initial stress of the spring 20 is adjusted by the adjusting screw 23, on which is screwed an internally screw-threaded sleeve 25, which has at its lower end a reentrant shoulder 26 for supporting the spring 29. To prevent a rotation about its axis, the sleeve 25 is provided with a laterally protruding nose 27, which engages a vertical groove 28 in the wall of the bore 18. A rotation of the screw 23 in one direction or the other will cause an upward or downward movement of the sleeve 25 to relax or compress the spring 20.

In addition to the torsion-responsive locking device described, a second locking device is provided, which consists also of a detent ball 2?, which by the compression spring 3%) is urged against the snap hole 31 in the intermediate portion of the guide rail 17. The snap hole 31 serves as a locking means for the ball 29 and for this purpose is provided with an upturned rim 32, like the hole 21. The detent ball 29 and the compression spring 30, the force of which can be adjusted by means of the adjusting screw 33, are accommodated in the hollow pivot pin 13, about which the jaw head 14 is pivotally movable.

Like the screw 23, the screw 33 has screwed on it an internally screw-threaded sleeve 35. The surface of the sleeve 35 is formed with a vertical groove 36, which receives a headless screw, in threaded engagement with the wall of the hollow pivot pin 13, for locking the sleeve 35 against rotation about its axis. The headless screw 37 is screwed into the pivot pin 13 before the latter is inserted into the jaw head 14, but after the screw 33 with sleeve 35 has been inserted. The screw 33 has the same function as the screw 2-3.

At its end facing the toe of the boot, the jaw head 14 is provided with the sole holder 38, which has a protruding edge 39 overlying the sole of the boot. The sole holder is screwed by means of a screw-threaded hole 40 onto an adjusting screw 41, which is rotatably mounted between the protruding lugs 42, 43 of the jaw head 14 and locked against rotation about its axis. At its upper end protrudingfrom the jaw head 14, the screw 41 has a grip 44, by which the screw 41 can be rotated to effect a vertical adjustment of the sole holder 38. The sole holder 38 is mounted to be pivotally movable about the adjusting screw 41' and is held in its intermediate position by a push button 45, which is axially slidably mounted in a bore 46 extending in the longitudinal direction of the ski and by a coil spring 47 inserted in said bore is forced against the curved b ack face 48 of the sole holder 38. The coil spring 47 is least compressed when the sole holder is in its intermediate position. If the sole holder 38 ispivotally moved in one direction or the other, the push button 45 will be pushed into th bore 4-6 against the force of the spring 47, the force of which is thus increased and tends to return the button 45 and with it the sole holder 38 into its original position.

Regarding the assembly of the safety jaw 12, the hollow pin 13 is inserted in a bore 49 of the base 15 and underlies the same with its outturned edge 50. The base 15 has inturned edges 55, which embrace the longitudinal edges of the guide rail 17. The screws 23 and 33 are urged upwardly by the springs and 30 and with their shoulders 51 and 52, respectively, bear on the shoulders 53 and 54, respectively.

The described ski safety binding with the described safety jaw according to the invention operates as follows:

, By means of the tightener 9, the boot 3 is gripped in known manner and by the tension cable 4 is forced against the safety jaw 12 and retained in clamped position. An excessive torsional load on the leg in the gripped boot 3 will cause the locking ball 19 to be lifted against the force of the compression spring 20 to slide to the left or right over the rim 22 of the snap hole 21. Thus, the jaw head14 is pivotally moved about the pivot pin 13 so that the sole holder 38 releases the boot 3.

On the other hand, in the case of an excessive flexural load, ,e.g., of a forward fall, a force occurs which tends to lift the heel 2 of the boot 3. by the retaining force of the tension cable 4 and a compressive force results, which by the stiff sole 11 of the boot 3 applies pressure on the sole holder 38 of the jaw head 14. If this force is sufficient, the detent ball 29 will be lifted against the force of the compression spring 39 to slide over the rim 32 of the snap hole 31. As a result, the jaw head 14 will slide forwardly in the guide rails 17 under the action of said compressive force and the sole holder 38 will release the boot 3. A rotation of the adjusting screws 23 or. 33 enables ,an adjustment of the pressure exerted by the compression springs 20 or 30 on the detent balls 19 and 29, respectively, so that the maximum torsional and flexural loads causing the jaw head 14 to release the boot 3 in the described manner are adjusted asdesired.

The safety jaw according to this invention may be used with a usual tension cable, which incorporates springs, for instance, for touring skiers and for downhill skiers having less practice, or with an entirely non-resilient tension cable incorporating no springs, for instance, for racing skiers. In conjunction with a non-resilient tension cable, the safety jaw will firmly grip the boot, like the so-called long-strap binding, but as contrasted with the This force is opposed latter will release the boot even in the case of an excessive flexural load, for instance, during a forward fall.

The invention is not restricted to the described safety jaw, which has the nature of a double-acting safety jaw by having a flexure-responsive locking device and a torsion-responsive locking device, which devices yield to excessive fiexural and torsional loads, respectively. The safety jaw may be designed only with a flexure-rcsponsive locking device according to the invention whereas the protection against excessive torsional loads is assigned to other elements'of the ski safety binding. Besides, the locking device may be of any other desired design and may comprise, e.g., a spring having a head which extends into an appropriate opening and yields to an excessive load.

What is claimed is:

1. A ski safety binding for releasably holding a skiing boot on a ski, comprising a safety jaw aflixed to a ski for retaining the end of the sole of a boot, means for urging a boot against said safety jaw, said safety jaw including a baseplate fixedly secured to the ski and slide means, and a jaw head mounted on said baseplate for rotation about an axis vertical to said ski, said jaw head being mounted on said slide means for movement along the baseplate in the longitudinal direction of the ski independently of its rotational movement, and two mutually independently acting snap locking devices, each of which comprises a spring-loaded detent on said jaw head acting in a vertical direction and having a curved surface engaged in a relatively fixed depressiomone of said locking devices being operative to release the jaw head for pivotal movement when the jaw head is subjected to a torsional overload but being inoperative to efiect such release during a longitudinal displacement of the jaw head, the other of said locking devices being operative to release the jaw head for longitudinal displacement when the jaw head is sub- 7 jected to a flexural overload and being inoperative to effect such release during a rotational movement of the jaw head. 7

2. A ski safety binding according to claim 1 wherein one of said depressions is located in said slide means and the other depression is located in said baseplate.

3. A ski safety binding as set forth in claim 1, wherein References Cited by the Examiner UNITED STATES PATENTS 2,899,211 8/59 Salomon 280-11.35 2,950,119 8/60 Gembruch 280-1135 3,029,085 4/62 Berlenbach 780-1135 FOREIGN PATENTS 204,938 8/59 Austria. 1,126,948 8/56 France. 1,229,272 3/60 France. 1,247,241 10/60 France.

v A. HARRY LEVY, Primary Examiner, 

1. A SKI SAFETY BINDING FOR RELEASABLY HOLDING A SKIING BOOT ON A SKI, COMPRISING A SAFETY JAW AFFIXED TO A SKI FOR RETAINING THE END OF THE SOLE OF A BOOT, MEANS FOR URGING A BOOT AGAINST SAID SAFETY JAW, SAID SAFETY JAW INCLUDING A BASEPLATE FIXEDLY SECURED TO THE SKI AND SLIDE MEANS, AND A JAW HEAD MOUNTED ON SAID BASEPLATE FOR ROTATION ABOUT AN AXIS VERTICAL TO SAID SKI, SAID JAW HEAD BEING MOUNTED ON SAID SLIDE MEANS FOR MOVEMENT ALONG THE BASEPLATE IN THE LONGITUDINAL DIRECTION OF THE SKI INDEPENDENTLY OF ITS ROTATIONAL MOVEMENT, AND TWO MUTUALLY INDEPENDENTLY ACTING SNAP LOCKING DEVICES, EACH OF WHICH COMPRISES A SPRING-LOADED DETENT ON SAID JAW HEAD ACTING IN A VERTICAL DIRECTION AND HAVING A CURVED SURFACE ENGAGED IN A RELATIVELY FIXED DEPRESSION, ONE OF SAID LOCKING DEVICES BEING OPERATIVE TO RELEASE THE JAW HEAD FOR PIVOTAL MOVEMENT WHEN THE JAW HEAD IS SUBJECTED TO A TORSIONAL OVERLOAD BUT BEING INOPERATIVE TO EFFECT SUCH RELEASE DURING A LONGITUDINAL DISPLACEMENT OF THE JAW HEAD, THE OTHER OF SAID LOCKING DEVICES BEING OPERATIVE TO RELEASE THE JAW HEAD IS SUBFOR LONGITUDINAL DISPLACEMENT WHEN THE JAW HEAD IS SUBJECTED TO A FLEXURAL OVERLOAD AND BEING INOPERATIVE TO EFFECT SUCH RELEASE DURING A ROTATIONAL MOVEMENT OF THE JAW HEAD. 